Research ArticleSpectrogram Analysis of Complete Dentures with DifferentThickness and Palatal Rugae Materials on Speech Production

Hamada Zaki Mahross1,2 and Kusai Baroudi2

1Department of Removable Prosthodontics, College of Dentistry, Al-Azhar University, Cairo, Egypt2Department of Restorative Dental Sciences, Alfarabi Colleges, Riyadh, Saudi Arabia

Correspondence should be addressed to Kusai Baroudi; d kusai@yahoo.co.uk

Received 25 December 2014; Revised 12 March 2015; Accepted 19 March 2015

Academic Editor: Manal Awad

Copyright © 2015 H. Zaki Mahross and K. Baroudi. This is an open access article distributed under the Creative CommonsAttribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work isproperly cited.

Objective. To investigate the influence of reproduction of different thickness andpalatal rugaematerials on complete dentures speechusingComputerized Speech Lab (CSL) (spectrogram).Materials andMethods.Three completely edentulousmale patients (aged 50–60 years) were selected for reading a paragraph. Twelve upper dentures were constructed, four for each patient.The patients’ speechgroups were divided into five groups, Group I: patients without dentures; Group II: patients rehabilitated with conventional acrylicdentures; Group III: patients with conventional acrylic dentures with rugae reproduction; Group IV: patients with dentures withmetallic framework of minimal thickness and direct ragged metallic palatal surface at rugae area; Group V: patients with dentureswith palatal rugae constructed from resilient acrylic resin material with thickness less than conventional denture. Speech sampleswere recorded after insertion of each denture for groups using Computerized Speech Lab (CSL) (spectrogram).The sounds selectedwere lingopalatal /s/z/sh/t/d/ and /l/. Results. Group III produced high mean significant difference with /sh/t/ sound. For Group IV,the difference was noticed with /s/z/sh/t/ and /d/ sounds, while for Group V the difference was shown with /z/l/ sound (𝑃 < 0.05).Conclusion. It is recommended to reproduce the rugae area in complete denture because the phonetic quality of complete denturewith rugae is superior to the conventional denture.

1. Introduction

Speech is essential to human activity as it is an importantfunction of the stomatognathic system, which uses the oralcavity as a part of the vocal apparatus. The voice is producedin the larynx with the aid of the vocal cords vibrating dueto the expiratory airflow. The frequency of the fundamentallaryngeal tone is dependent on the vocal cord tension, whichthen modulated in the resonance cavities and their shapeconditioning the vowel formants [1, 2].

The speech articulatory organs include the tongue, palate,alveolar processes, gums, teeth, and lips. The teeth, alveolus,and palate are static components of speech articulationwhereas tongue, lip, and velum are dynamic components.Therefore, phonetics must be considered with mechanics andesthetics as the cardinal factors contributing to the success ofthe dental prosthesis [2, 3].

Complete loss of teeth can cause persistent speech dis-orders by altering dental articulation areas that will severely

reduce the quality of speech; particularly the alteration offrontal maxillary morphology leads to impairment of speechproduction [4].

Removable complete dentures can partly solve this prob-lem. However, they disturb speech production themselvesas they restrict the flexibility of the tongue, narrow the oralcavity, and alter the articulation areas of the palate and teeth[5, 6].

Dentures should bemade to enable the patient to producevoice and speech without deficiencies. About 25% of patientsin clinical dentistry are considered to suffer from temporaryor permanent changes in articulation due to the applicationof removable dentures. Articulatory errors may be due todenture factors like altered vertical dimension, size, andposition of the teeth, thickness, and contour of the denturebase [1, 2].

Accurate approximation of palatal contours of amaxillarycomplete denture to a patient’s tongue can improve speech

Hindawi Publishing CorporationInternational Journal of DentistryVolume 2015, Article ID 606834, 5 pageshttp://dx.doi.org/10.1155/2015/606834

2 International Journal of Dentistry

intelligibility, if other factors such as tooth position, occlusalplane, and occlusal vertical dimension are satisfactory [7].

Pound, in 1950, stated that anterior palatal region playsan important role in pronunciation of consonants. He termedit as “playground” of tongue because 90% of tongue’s rapidmanipulation while talking was restricted to this area andarea lingual to lower anterior teeth [8].

The artificial palatal vaults of maxillary dentures oftenhave a concave shape. In contrast, natural palatal vaultsare of convex shape in the alveolar region. So the palatalvaults of maxillary dentures should be shaped like naturalones to facilitate correct pronunciation and the quality ofspeech sound production improvedwithin the first week afterinsertion of new dentures [9].

The most important instruments for the investigationof speech sound production are the trained hearing ofa speech and language professional, spectral analysis, andpalatographics [4, 10, 11].

Spectral analysis has been used to examine the effects ofdental prostheses on speech sound production. With theuse of spectral analysis, a sound event can be split intothree dimensions: frequency, amplitude, and chronologicsequence. The data obtained can be visualized in 2-dimen-sional Cartesian coordinates with the color or grey shade asthe third dimension. Although less common, a 3-dimensionalprofile representation can be used instead [4, 5, 11, 12].

Studies on speech sound production may have a clinicalimpact because many patients attach great importance toundisturbed speech sound production after dental treatmentand Heyink et al. found that 28 (21%) of 131 denture wearingindividuals from an elderly population had speech problems.Speech production has a significant effect on patients’ generalsatisfaction with dentures [13].

The aim of this study was to investigate the influence ofreproduction of different palatal rugae materials and thick-ness on complete dentures speech using spectrogram.

2. Materials and Methods

Three completely edentulous male patients, aged 50–60,were selected from the Outpatient Clinic of ProsthodonticsDepartment, Faculty of Dental Medicine, Al-Azhar Univer-sity (ethical approval number 589/2012).The selected patientsmust be free from any systemic diseases or any dentalproblems and must be able to read in a regular manner forreading the paragraph. Patients consent was obtained.

Twelve complete upper dentures were incorporated inthis study; four upper complete dentureswith different palatalrogue changes for each patientwere constructed.Thepatients’speech records in this study were divided into five groups,Group I: patients without denture, Group II: patients withupper acrylic denture having polished anterior palatal surfacewithout rugae reproduction in usual thickness (2–2.5mm),Group III: patients with conventional upper acrylic denturewith rugae reproduction on its polishing surfaces in usualthickness (2–2.5mm), Group IV: patients withmetallic upperdenture base of minimal thickness (0.5–1mm) and directragged metallic palatal surface at rugae area, and Group V:patients with upper denture having palatal rugae constructed

from resilient acrylic resin material with thickness less thanconventional denture (1.5–2mm).

The dentures in Groups III, IV, and V were made byduplicating the denture previously constructed to Group IIto preserve the same tooth position, occlusal plane, verticaldimension, and denture base thickness for each patient. Afterthat, the duplicated denture was used as trial denture as therugae reproduction was performed.

2.1. Reproduction of the Rugae Area. Two maxillary alginateimpressions were made for a patient with prominent palatalrugae. The first impression was poured with stone to beused as a palatal rugae replica. The second impression wasperformed as the area of rugae in the impression was pouredwith softened wax to make a palatal rugae template. The waxwas removed from the impression and sealed on the polishingsurface of the trial duplicated denture base at the area ofrugae.

The trial denture was processed in the usual manner,finally finishing and polishing the final denture with its rugae.

The patient adaptation period must be about two weeksto avoid any mistake of new denture problems. According toInukai et al. the speech adaptation to new complete denturenormally takes place within 2 to 4 weeks after insertion [14].

2.2. Methods of Measurements. Speech samples were record-ed after insertion of each denture for groups using Comput-erized Speech Lab (CSL) (spectrogram) (CSL Kay ElemetricsModel 4300, USA) in Phoneatric Unit, ENT Department,Specialized Ain-Shams Hospital.

After the period of adaptation, the sound recordings wereperformed in a special room phonically isolated with thepatient speaking in a sensible microphone. A microphoneproduces a time-varying electrical voltage that is proportionalto the increase or decrease in local pressure that constitutessound. This continuous time-varying voltage is an electricanalog of the acoustic signal [15]. The patients were askedto sit in upright position to allow reading of a passage incomfortable amplitude and pitch. Distance frommicrophoneis about 10 cm to avoid a lot of stochastic noise.

The set unit CSL consists of external module with highspeed dual channel, the plug-in board with 2 high speeddigital signal processing integrated circuits, high qualitymicrophone, and software version 3.1 and all patients weresubjected to analysis of their signal after it is captured usingsampling rate of 20KHz and bandwidth is 300. The contin-uous electric signal can be converted to a digital represen-tation suitable for manipulation by a computer. Computersequipped with the proper hardware can convert the analogvoltage variations into digital sound waveforms by a processcalled analog-to-digital conversion.

The higher the sampling rate, the better the sound quality,but the more the bits required. There is a direct relationshipbetween the accuracy of quantization and the number of bitsrequired [4, 15].

The tested sounds selected were /S/ unvoiced linguoden-tal fricative; /Sh/ unvoiced linguoalveolar fricative; /z/ voicedlinguoalveolar fricative; /t/ unvoiced linguoalveolar stop; /d/voiced linguoalveolar stop; /l/ voiced linguoalveolar stop.

International Journal of Dentistry 3

Table 1: Comparison between the studied groups according to sounds measured by the maximum energy (frequency, HZ).

Sounds Group (𝑛 = 3) Group I (𝑛 = 3) Group II (𝑛 = 3) Group III (𝑛 = 3) Group IV (𝑛 = 3)S (Hz) 1053.7 ± 54.3 1264.2 ± 69.5 1203.6 ± 46.4 1313.4 ± 55.5 1234.8 ± 48.7Z (Hz) 834.9 ± 55.5 963.6 ± 54.2 1022.5 ± 45.6 1444.0 ± 82.8 1097.0 ± 41.6Sh (Hz) 1205.8 ± 68.0 1170.6 ± 65.1 1291.0 ± 67.8 1326.9 ± 72.3 1237.0 ± 65.9T (m/sec.) 4.33 ± 0.1 3.47 ± 0.1 4.47 ± 0.2 4.53 ± 0.1 3.53 ± 0.1D (m/sec.) 5.77 ± 0.1 1.90 ± 0.1 3.83 ± 0.1 4.57 ± 0.2 4.57 ± 0.2L (m/sec.) 6.97 ± 0.1 4.50 ± 0.1 4.33 ± 0.2 4.40 ± 0.1 4.67 ± 0.1

These sounds were selected in a paragraph to avoid thepatient trials to adjust himself for optimum utterance. Thespectral analysis was not done on the whole word of theparagraph but only onword fragments that permit perceptionof these alterations as /s/sh/z/t/d/ and /l/ sounds. Breakingthe words into sounds was performed for each patient inorder to achieve more profound study of individual phoneticcharacteristics and a higher quality of studied phenomena.

The spectral analysis of the taken signal was measured bythe maximum energy (frequency, HZ) for /s/, /sh/, and /z/sounds. However, for /t/d/ and /l/ sounds, it was measuredby time interval (m/sec.) because they have less voice onsettime for adaptive patient speak.The data were obtained usingvertical and horizontal cursors on the screen.

2.3. Statistical Analysis. Data were statistically analyzed byone-way ANOVA followed by Tukey’s post hoc test at thesignificance level of 𝛼 = 0.05.

3. Results

Data of the tested groupswas presented asmean and standarddeviation (SD) values (Table 1).

The collected data for /s/ sound in five groups showed thatthe highest mean value was observed with Groups IV andII, and the lowest mean value was with Group I. For the /z/sound, the highestmean value was withGroups IV andV andthe lowest mean value was with Group I. For /sh/ sound, thehighest mean value was with Groups IV and V and the lowestmean value was with Group II (Figure 1). For /t/ sound, thehighestmean valuewaswithGroups IV and III and the lowestmean value was with Group II. For /d/ sound, Groups I andIV showed the highest mean value, and Group II showed thelowest mean value. For /l/ sound, Groups V and I showed thehighest mean value and Group III showed the lowest meanvalue (Figure 2).

The reproduction of rugae area in acrylic denture (GroupIII) produced highly significant difference with /t/ soundand significant difference with /sh/z/ and /d/ sounds andlowest significant difference with /l/ sound (𝑃 < 0.05).In the denture with metallic base, Group IV produceshighly significant difference with /s/z/sh/t/ and /d/ soundsand significant differences with /l/ sound (𝑃 < 0.05). InGroup V denture with resilient acrylic rugae produces highlysignificant difference with /z/sh/l/d/ sound and significantdifferences with /s/t/ sound (𝑃 < 0.05). Moreover, speakingwithout denture or with conventional denture without rugae

0

200

400

600

800

1000

1200

1400

1600

I II III IV V

shz

s

Group

Figure 1: Comparison between the studied groups according to/sh/z/t/ sounds measured by the maximum energy (frequency, HZ).

0

1

2

3

4

5

6

7

8

DL

T

I II III IV VGroup

Figure 2: Comparison between the studied groups according to/d/l/t sounds measured by time interval (m/sec.).

produced the lowest significance with all tested /s/z/sh/t/d/sounds except /l/ sound (𝑃 < 0.05).

4. Discussion

Thepresent study discusses the changes of the denture factorssuch as proper rugae shaping and base thickness for adequate

4 International Journal of Dentistry

tongue space and articulation. If it is determined that thetongue is a possible source of the speech problem, a structuralchange in the denture should be considered.

Speech problems are frequently reported after completedenture placementmainly expressed as problemswith conso-nants, especially lingopalatal sounds [16]. So, the lingopalatalsounds were analyzed in the present study. Some patientshad a remarkable adaptive capacity after repeating 5-6 keywords. Analyzed spectrograms are different by frequency(lowor high) of emitted sounds related to the denture changesand oral resonance cavity [17]. Specific letters were selectedbecause not all the letters can be verified. According toSinescu et al., some sounds such as /z/s/t/ and /sh/ are moresensible and more often compromised due to the changesof oral structures and because of the demand for moreprecise articulationmovements.Therefore, these soundswerestudied in this work [18].

Attempts to rebuild the rugae palatinae are controversial.It was suggested that the tongue needs surfaces with greatertactile stimulation in analogy to the anatomic structures [17].

The importance of palatal rugae in complete dentureconstruction for proper sound production was revealed bythis study.This comes with the agreement of the study, whichadvocated developing a normal /s/ and /sh/ sounds, andit may be necessary to thicken the incisive papilla regionto prevent the jet of air emitted by the median sulcus ofthe tongue from escaping toward the vault. Bulking of thetongue palatal contact area and the area of the incisive papillawill facilitate proper enunciation and eliminate much of thepostinsertion practice period [7, 19].

The metallic dentures selected to provide minimal crosssection enhance maximum space for sound production. Theessential factor in production of correct /s/ is the propergrooving of the tongue. As the depth of this groove decreased,/s/ is pronounced toward /sh/ as a lisp [20]. Therefore, asin this study, when using metallic denture base, a minimalthickness faced the tongue permitting its proper grooving.

Foti et al. investigate the speech of two edentuloussubjects fitted with a complete maxillary prosthesis madeof three different palatal materials: aluminium, resin, andstellite. These recordings were tested from the auditory pointof view by a series of six listeners (four men and twowomen) in an anechoic room.The results show that the groupfitted with a metal prosthesis (aluminum, stellite) was moreintelligible regarding the way they were perceived by others[21].

Evaluation of the speech was performed by acoustic anal-ysis and intelligibility analysis. Reports of acoustic analysisrevealed that pronunciation of “s,” “sh,” “t,” and “d” was clearerwith rugae incorporated denture than conventional denture.Customized rugae dentures were better than arbitrary rugaedentures. Intelligibility reports showed many substitutionalerrors with conventional denture. With customized rugaedenture speech was clearer [2]. These results agree with theresult of this study.

Allen stated that the most widely used procedure toimprove denture phonetics is the random thinning of theentire maxillary lingual surface to create more space forthe tongue. Such arbitrary removal of acrylic resin from

the palatal surface ignores the critical importance of correctpalatal contours in the proper formation of sounds [19].This finding disagrees with the result obtained from thisstudy, because this opinion may be correct in case of lowerdenture to restore critical tongue space and thinning ofacrylic denture may cause fracture.

The results of this study coincide with the result reportedby Ravishankar and Singh as they reported that the lin-gopalatal (anterior) sounds /c/ (soft), /d/t/n/s/z/, and /r/ areformed by the contact of the tip of the tongue with the mostanterior part of the palate called the alveolus or the lingualside of anterior teeth. If the denture base in the rugae area istoo thick, the /t/ in “tend” sounds like /d/ and the /d/ soundslike /t/ [22].

The patient emotional behavior in relation to a prosthetictreatment can also influence the speech patterns. Patients,who psychologically accepted their dentures, shortly afterthey started wearing them, also had fewer speech difficultiesthan those who did not accept the dentures [14] and for thisreason, the adaptation period was used in this study.

Therefore, in the adaptation period, a series of speechdefects may be noted as hypernasality. As the patient useshis custom-made prosthesis with accurate biomechanicaland physiological properties, these complaints decrease andelimination of these problems can be noted over time [23].

The character of speech sounds is difficult to be analyzedand interpreted but it is detectedwith accuracy by the hearingsense, which is a more sensitive analysis device than well-knownhandmade devices [24].This result is not in agreementwith the study, as the computerized device is more accuratethan hearing sense.

Important investigations of speech sounds are based onthe Fourier spectrumandon the short-timeFourier spectrum(spectrogram). The most accurate measurements methodswere, as this study suggested, by Jindra et al. [1], Kobayashiet al. [25], and Ogutcen-Toller [26] who chose speech soundsanalysis by using standard signal processing methods. Themethod with the best results was the Fourier method. Itsevaluation of the studied phenomena is both qualitativelyand quantitatively valuable making the reproducibility of theanalysis applicable [17]. So the sample size of three instead offivewas used.TheFouriermethod for the phonetic evaluationwas used because its graphic correspondence is simple andfacile to translate. The phonetic alterations are consideredclassic for the human voice and could also be representedeven for the higher spectrum. In the present study, thespectrogram was used [17].

5. Conclusion

It is recommended to reproduce the rugae area in completedenture because the phonetic quality of complete denturewith rugae was superior to the conventional denture. If thedenture was too thick in the anterior region, the result wouldbe a faulty /sh/d/z/t/l/ sound.The dentures with metallic basecan enhance /s/sh/t/d/ and /z/ sounds. The use of resilientacrylic to reproduce the rugae in complete denture canenhance /z/l/s/sh/t/ and /d/ sounds.

International Journal of Dentistry 5

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper.

Authors’ Contribution

Hamada Zaki Mahross (guarantor) performed literaturesearch, paper preparation, and data acquisition. Kusai Ba-roudi performed data analysis and statistical analysis andpaper editing and review.

References

[1] P. Jindra,M. Eber, and J. Pesak, “The spectral analysis of syllablesin patients using dentures,” Biomedical Papers, vol. 2, pp. 91–94,2002.

[2] R. Adaki, S. Meshram, and S. Adaki, “Acoustic analysis andspeech intelligibility in patients wearing conventional den-tures and rugae incorporated dentures,” The Journal of IndianProsthodontist Society, vol. 13, no. 4, pp. 413–420, 2013.

[3] V. Krishna, V. V. K. Reddy, N. P. Kumar, andK. V. K. Raju, “Den-tures with phonetically contoured palate: a simple technique ofadding customized rugae and palatal contours to the maxillarydenture,” The Journal of Contemporary Dental Practice, vol. 13,no. 2, pp. 216–218, 2012.

[4] F. Stelzle, B. Ugrinovic, C. Knipfer et al., “Automatic, computer-based speech assessment on edentulous patients with andwithout complete dentures—preliminary results,” Journal ofOral Rehabilitation, vol. 37, no. 3, pp. 209–216, 2010.

[5] C. Runte, D. Tawana, D. Dirksen et al., “Spectral analysis of/s/ sound with changing angulation of the maxillary centralincisors,” International Journal of Prosthodontics, vol. 15, no. 3,pp. 254–258, 2002.

[6] Z. Dubravka Knezovic and A. Celebic, “Factors related topatients’ general satisfaction with removable partial dentures:a stepwise multiple regression analysis,” International Journal ofProsthodontics, vol. 21, no. 1, pp. 86–88, 2008.

[7] H.-J. Kong and C. A. Hansen, “Customizing palatal contoursof a denture to improve speech intelligibility,” The Journal ofProsthetic Dentistry, vol. 99, no. 3, pp. 243–248, 2008.

[8] E. Pound, “Esthetic dentures and their phonetic values,” TheJournal of Prosthetic Dentistry, vol. 1, no. 1-2, pp. 98–111, 1951.

[9] H. Tanaka, “Speech patterns of edentulous patients and mor-phology of the palate in relation to phonetics,” The Journal ofProsthetic Dentistry, vol. 29, no. 1, pp. 16–28, 1973.

[10] A. Lohmander and M. Olsson, “Methodology for perceptualassessment of speech in patients with cleft palate: a criticalreview of the literature,” Cleft Palate-Craniofacial Journal, vol.41, no. 1, pp. 64–70, 2004.

[11] R. Jacobs, E. Manders, C. van Looy, D. Lembrechts, I. Naert,and D. van Steenberghe, “Evaluation of speech in patientsrehabilitated with various oral implant-supported prostheses,”Clinical Oral Implants Research, vol. 12, no. 2, pp. 167–173, 2001.

[12] J. M. Palmer, “Analysis of speech in prosthodontic practice,”TheJournal of Prosthetic Dentistry, vol. 31, no. 6, pp. 605–614, 1974.

[13] J. Heyink, J. Heezen, and R. Schaub, “Dentist and patientappraisal of complete dentures in a Dutch elderly population,”Community Dentistry and Oral Epidemiology, vol. 14, no. 6, pp.323–326, 1986.

[14] S. Inukai, M. Hideshima, M. Sato et al., “Analysis of th re-lationship between the incisal overjet in a maxillary dentureand phonetic function using a speech recognition system,”Prosthodontic Research&Practice, vol. 5, no. 3, pp. 171–177, 2006.

[15] C. Bortun, M. Leretter, L. Sandu, D. Dodenciu, G. Draganescu,and C. Samoila, “Phonetic evaluation of the edentulous patientcorrelated with the various settings of the artificial teeth,”Serbian Dental Journal, vol. 51, pp. 93–96, 2004.

[16] A. J. Hassel and T. Holste, “Improving the speech functionof maxillary complete dentures: a pilot study,” InternationalJournal of Prosthodontics, vol. 19, no. 5, pp. 499–503, 2006.

[17] T. Ando,M. Hideshima, S. Inukai, Y. Igarashi, andH.Matsuura,“Analysis of the relationship between palatal contour and thephonetic function in complete denture wearers using a speechrecognition system,” Prosthodontic Research & Practice, vol. 5,no. 4, pp. 231–237, 2006.

[18] C. Sinescu, G. E. Draganescu, D. Dodenciu, L. Bereteu, M.Negrutiu, and M. Romanu, “Quantitative parameters whichdescribe speech sound distortions due to inadequate dentalmounting,” Physica A: Statistical Mechanics and Its Applications,vol. 387, no. 5-6, pp. 1205–1217, 2008.

[19] L. B. Allen, “Improved phonetics in artifical denture construc-tion.,” United States Armed Forces Medical Journal, vol. 10, pp.1022–1033, 1959.

[20] M. M. Silverman, “The whistle and swish sound in denturepatients,” The Journal of Prosthetic Dentistry, vol. 17, no. 2, pp.144–148, 1967.

[21] B. Foti, P. Tavitian, and J.-J. Bonfil, “Speech intelligibility inpatients with complete dentures according to thematerial used,”Journal of Oral Rehabilitation, vol. 25, no. 6, pp. 479–484, 1998.

[22] C. Ravishankar and G. Singh, “Phonetics and flight safety—anorodental view point,” Indian Journal of AerospaceMedicine, vol.46, pp. 54–58, 2002.

[23] M.Ozbek, I. Tulunoglu, S. Ozkan, andM.Oktemer, “Evaluationof articulation of Turkish phonemes after removable partialdenture application,” Brazilian Dental Journal, vol. 14, no. 2, pp.125–131, 2003.

[24] G. E. Draganescu, C. Sinescu, and D. Dodenciu, “Quantitativemeasurement of speech sound distortions due to inadequatedental mounting,” Computer Methods in Biomechanics andBiomedical Engineering, vol. 9, no. 1, pp. 25–34, 2006.

[25] M. Kobayashi, M. Oki, S. Ozawa et al., “Vibration analysis ofobturator prostheses with different bulb height designs,” Journalof Medical and Dental Sciences, vol. 49, no. 4, pp. 121–128, 2002.

[26] M. Ogutcen-Toller, “Sound analysis of temporomandibularjoint internal derangements with phonographic recordings,”Journal of Prosthetic Dentistry, vol. 89, no. 3, pp. 311–318, 2003.

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